Organocatalytic formal [5+1] annulation: diastereoselective cascade synthesis of functionalized six-membered spirocyclic indane-1,3-diones/oxindoles via Michael–aldol reaction
摘要:
An efficient cascade protocol has been developed for the diastereoselective synthesis of functionalized six-membered spirocyclic compounds. The reaction proceeded smoothly between indane 1,3-diones/oxindoles/coumaranone as the dinucleophilic components and (E)-5-nitro-6-aryl-hex-5-en-2-one as the dielectrophile to give the desired products with reasonable to high chemical yields (30-84%) and high levels of diastereoselectivities (upto >95:5 dr). The reaction proceeded smoothly via cascade Michael aldol reaction. (C) 2013 Elsevier Ltd. All rights reserved.
Rauhut–Currier type homo- and heterocouplings involving nitroalkenes and nitrodienes
作者:Pramod Shanbhag、Pradeep R. Nareddy、Mamta Dadwal、Shaikh M. Mobin、Irishi N. N. Namboothiri
DOI:10.1039/c0ob00062k
日期:——
Reaction of nitroalkenes or nitrodienes with methyl vinyl ketone (MVK) or acrylate in the presence of the imidazole–LiCl catalyst system provides Rauhut–Currier (vinylogous Morita–Baylis–Hillman) adducts in moderate yield. Under similar conditions (imidazole–hydroquinone), nitroalkenes and nitrodienes undergo self-dimerization to afford the Rauhut–Currier adducts in varying yields. An alternative